Multiple usb camera error

Please provide complete information as applicable to your setup.

• Hardware Platform (Jetson / GPU) Jetson Orin
• DeepStream Version 6.1 & 6.2
• Issue Type( questions, new requirements, bugs) question

#!/usr/bin/env python3

################################################################################
# SPDX-FileCopyrightText: Copyright (c) 2020-2022 NVIDIA CORPORATION & AFFILIATES. All rights reserved.
# SPDX-License-Identifier: Apache-2.0
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
################################################################################

import sys
sys.path.append('../')
import gi
gi.require_version('Gst', '1.0')
from gi.repository import GLib, Gst
from common.is_aarch_64 import is_aarch64
from common.bus_call import bus_call

import pyds

PGIE_CLASS_ID_VEHICLE = 0
PGIE_CLASS_ID_BICYCLE = 1
PGIE_CLASS_ID_PERSON = 2
PGIE_CLASS_ID_ROADSIGN = 3


def osd_sink_pad_buffer_probe(pad,info,u_data):
    frame_number=0
    #Intiallizing object counter with 0.
    obj_counter = {
        PGIE_CLASS_ID_VEHICLE:0,
        PGIE_CLASS_ID_PERSON:0,
        PGIE_CLASS_ID_BICYCLE:0,
        PGIE_CLASS_ID_ROADSIGN:0
    }
    num_rects=0

    gst_buffer = info.get_buffer()
    if not gst_buffer:
        print("Unable to get GstBuffer ")
        return

    # Retrieve batch metadata from the gst_buffer
    # Note that pyds.gst_buffer_get_nvds_batch_meta() expects the
    # C address of gst_buffer as input, which is obtained with hash(gst_buffer)
    batch_meta = pyds.gst_buffer_get_nvds_batch_meta(hash(gst_buffer))
    l_frame = batch_meta.frame_meta_list
    while l_frame is not None:
        try:
            # Note that l_frame.data needs a cast to pyds.NvDsFrameMeta
            # The casting is done by pyds.NvDsFrameMeta.cast()
            # The casting also keeps ownership of the underlying memory
            # in the C code, so the Python garbage collector will leave
            # it alone.
           frame_meta = pyds.NvDsFrameMeta.cast(l_frame.data)
        except StopIteration:
            break

        frame_number=frame_meta.frame_num
        num_rects = frame_meta.num_obj_meta
        l_obj=frame_meta.obj_meta_list
        while l_obj is not None:
            try:
                # Casting l_obj.data to pyds.NvDsObjectMeta
                obj_meta=pyds.NvDsObjectMeta.cast(l_obj.data)
            except StopIteration:
                break
            obj_counter[obj_meta.class_id] += 1
            try: 
                l_obj=l_obj.next
            except StopIteration:
                break

        # Acquiring a display meta object. The memory ownership remains in
        # the C code so downstream plugins can still access it. Otherwise
        # the garbage collector will claim it when this probe function exits.
        display_meta=pyds.nvds_acquire_display_meta_from_pool(batch_meta)
        display_meta.num_labels = 1
        py_nvosd_text_params = display_meta.text_params[0]
        # Setting display text to be shown on screen
        # Note that the pyds module allocates a buffer for the string, and the
        # memory will not be claimed by the garbage collector.
        # Reading the display_text field here will return the C address of the
        # allocated string. Use pyds.get_string() to get the string content.
        py_nvosd_text_params.display_text = "Frame Number={} Number of Objects={} Vehicle_count={} Person_count={}".format(frame_number, num_rects, obj_counter[PGIE_CLASS_ID_VEHICLE], obj_counter[PGIE_CLASS_ID_PERSON])

        # Now set the offsets where the string should appear
        py_nvosd_text_params.x_offset = 10
        py_nvosd_text_params.y_offset = 12

        # Font , font-color and font-size
        py_nvosd_text_params.font_params.font_name = "Serif"
        py_nvosd_text_params.font_params.font_size = 10
        # set(red, green, blue, alpha); set to White
        py_nvosd_text_params.font_params.font_color.set(1.0, 1.0, 1.0, 1.0)

        # Text background color
        py_nvosd_text_params.set_bg_clr = 1
        # set(red, green, blue, alpha); set to Black
        py_nvosd_text_params.text_bg_clr.set(0.0, 0.0, 0.0, 1.0)
        # Using pyds.get_string() to get display_text as string
        print(pyds.get_string(py_nvosd_text_params.display_text))
        pyds.nvds_add_display_meta_to_frame(frame_meta, display_meta)
        try:
            l_frame=l_frame.next
        except StopIteration:
            break
			
    return Gst.PadProbeReturn.OK	


def main(args):
    # Check input arguments
    if len(args) != 2:
        sys.stderr.write("usage: %s <v4l2-device-path>\n" % args[0])
        sys.exit(1)

    # Standard GStreamer initialization
    Gst.init(None)

    # Create gstreamer elements
    # Create Pipeline element that will form a connection of other elements
    print("Creating Pipeline \n ")
    pipeline = Gst.Pipeline()

    if not pipeline:
        sys.stderr.write(" Unable to create Pipeline \n")

    # Source element for reading from the file
    print("Creating Source \n ")
    source = Gst.ElementFactory.make("v4l2src", "usb-cam-source")
    if not source:
        sys.stderr.write(" Unable to create Source \n")

    caps_v4l2src = Gst.ElementFactory.make("capsfilter", "v4l2src_caps")
    if not caps_v4l2src:
        sys.stderr.write(" Unable to create v4l2src capsfilter \n")


    print("Creating Video Converter \n")

    # Adding videoconvert -> nvvideoconvert as not all
    # raw formats are supported by nvvideoconvert;
    # Say YUYV is unsupported - which is the common
    # raw format for many logi usb cams
    # In case we have a camera with raw format supported in
    # nvvideoconvert, GStreamer plugins' capability negotiation
    # shall be intelligent enough to reduce compute by
    # videoconvert doing passthrough (TODO we need to confirm this)


    # videoconvert to make sure a superset of raw formats are supported
    vidconvsrc = Gst.ElementFactory.make("videoconvert", "convertor_src1")
    if not vidconvsrc:
        sys.stderr.write(" Unable to create videoconvert \n")

    # nvvideoconvert to convert incoming raw buffers to NVMM Mem (NvBufSurface API)
    nvvidconvsrc = Gst.ElementFactory.make("nvvideoconvert", "convertor_src2")
    if not nvvidconvsrc:
        sys.stderr.write(" Unable to create Nvvideoconvert \n")

    caps_vidconvsrc = Gst.ElementFactory.make("capsfilter", "nvmm_caps")
    if not caps_vidconvsrc:
        sys.stderr.write(" Unable to create capsfilter \n")

    # Create nvstreammux instance to form batches from one or more sources.
    streammux = Gst.ElementFactory.make("nvstreammux", "Stream-muxer")
    if not streammux:
        sys.stderr.write(" Unable to create NvStreamMux \n")

    # Use nvinfer to run inferencing on camera's output,
    # behaviour of inferencing is set through config file
    pgie = Gst.ElementFactory.make("nvinfer", "primary-inference")
    if not pgie:
        sys.stderr.write(" Unable to create pgie \n")

    # Use convertor to convert from NV12 to RGBA as required by nvosd
    nvvidconv = Gst.ElementFactory.make("nvvideoconvert", "convertor")
    if not nvvidconv:
        sys.stderr.write(" Unable to create nvvidconv \n")

    # Create OSD to draw on the converted RGBA buffer
    nvosd = Gst.ElementFactory.make("nvdsosd", "onscreendisplay")

    if not nvosd:
        sys.stderr.write(" Unable to create nvosd \n")

    # Finally render the osd output
    if is_aarch64():
        print("Creating nv3dsink \n")
        sink = Gst.ElementFactory.make("nv3dsink", "nv3d-sink")
        if not sink:
            sys.stderr.write(" Unable to create nv3dsink \n")
    else:
        print("Creating EGLSink \n")
        sink = Gst.ElementFactory.make("nveglglessink", "nvvideo-renderer")
        if not sink:
            sys.stderr.write(" Unable to create egl sink \n")

    print("Playing cam %s " %args[1])
    caps_v4l2src.set_property('caps', Gst.Caps.from_string("video/x-raw, framerate=30/1"))
    caps_vidconvsrc.set_property('caps', Gst.Caps.from_string("video/x-raw(memory:NVMM)"))
    source.set_property('device', args[1])
    streammux.set_property('width', 1280)
    streammux.set_property('height', 720)
    streammux.set_property('batch-size', 1)
    streammux.set_property('batched-push-timeout', 4000000)
    pgie.set_property('config-file-path', "dstest1_pgie_config.txt")
    # Set sync = false to avoid late frame drops at the display-sink
    sink.set_property('sync', False)

    print("Adding elements to Pipeline \n")
    pipeline.add(source)
    pipeline.add(caps_v4l2src)
    pipeline.add(vidconvsrc)
    pipeline.add(nvvidconvsrc)
    pipeline.add(caps_vidconvsrc)
    pipeline.add(streammux)
    pipeline.add(pgie)
    pipeline.add(nvvidconv)
    pipeline.add(nvosd)
    pipeline.add(sink)

    # we link the elements together
    # v4l2src -> nvvideoconvert -> mux -> 
    # nvinfer -> nvvideoconvert -> nvosd -> video-renderer
    print("Linking elements in the Pipeline \n")
    source.link(caps_v4l2src)
    caps_v4l2src.link(vidconvsrc)
    vidconvsrc.link(nvvidconvsrc)
    nvvidconvsrc.link(caps_vidconvsrc)

    sinkpad = streammux.get_request_pad("sink_0")
    if not sinkpad:
        sys.stderr.write(" Unable to get the sink pad of streammux \n")
    srcpad = caps_vidconvsrc.get_static_pad("src")
    if not srcpad:
        sys.stderr.write(" Unable to get source pad of caps_vidconvsrc \n")
    srcpad.link(sinkpad)
    streammux.link(pgie)
    pgie.link(nvvidconv)
    nvvidconv.link(nvosd)
    nvosd.link(sink)

    # create an event loop and feed gstreamer bus mesages to it
    loop = GLib.MainLoop()
    bus = pipeline.get_bus()
    bus.add_signal_watch()
    bus.connect ("message", bus_call, loop)

    # Lets add probe to get informed of the meta data generated, we add probe to
    # the sink pad of the osd element, since by that time, the buffer would have
    # had got all the metadata.
    osdsinkpad = nvosd.get_static_pad("sink")
    if not osdsinkpad:
        sys.stderr.write(" Unable to get sink pad of nvosd \n")

    #osdsinkpad.add_probe(Gst.PadProbeType.BUFFER, osd_sink_pad_buffer_probe, 0)

    # start play back and listen to events
    print("Starting pipeline \n")
    pipeline.set_state(Gst.State.PLAYING)
    try:
        loop.run()
    except:
        pass
    # cleanup
    pipeline.set_state(Gst.State.NULL)

if __name__ == '__main__':
    sys.exit(main(sys.argv))

Using the code above in file “deepstream_test_1_usb.py”, I can access the single usb camera. However, when I try to run a loop on multiple camera setup (4 usb camera). I get the following error -

Error: gst-stream-error-quark: Internal data stream error. (1): gstbasesrc.c(3072): gst_base_src_loop (): /GstPipeline:pipeline0/GstBin:source-bin-00/GstV4l2Src:usb-cam-source:
streaming stopped, reason not-linked (-1)
Exiting app

Can someone help me on how to run the model on deepstream with multiple usb camera, specially how to link?

The code I am using to run multiple usb camera is following -

#!/usr/bin/env python3

################################################################################
# SPDX-FileCopyrightText: Copyright (c) 2020-2022 NVIDIA CORPORATION & AFFILIATES. All rights reserved.
# SPDX-License-Identifier: Apache-2.0
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
################################################################################

import sys
sys.path.append('../')
import gi
gi.require_version('Gst', '1.0')
from gi.repository import GLib, Gst
from common.is_aarch_64 import is_aarch64
from common.bus_call import bus_call

import pyds

PGIE_CLASS_ID_VEHICLE = 0
PGIE_CLASS_ID_BICYCLE = 1
PGIE_CLASS_ID_PERSON = 2
PGIE_CLASS_ID_ROADSIGN = 3

def create_source_bin(index,uri,pipeline):
    # Source element for reading from the file
    print("Creating Source \n ")
    source = Gst.ElementFactory.make("v4l2src", str(index))
    if not source:
        sys.stderr.write(" Unable to create Source \n")

    caps_v4l2src = Gst.ElementFactory.make("capsfilter", "v4l2src_caps")
    if not caps_v4l2src:
        sys.stderr.write(" Unable to create v4l2src capsfilter \n")


    print("Creating Video Converter \n")

    # Adding videoconvert -> nvvideoconvert as not all
    # raw formats are supported by nvvideoconvert;
    # Say YUYV is unsupported - which is the common
    # raw format for many logi usb cams
    # In case we have a camera with raw format supported in
    # nvvideoconvert, GStreamer plugins' capability negotiation
    # shall be intelligent enough to reduce compute by
    # videoconvert doing passthrough (TODO we need to confirm this)


    # videoconvert to make sure a superset of raw formats are supported
    vidconvsrc = Gst.ElementFactory.make("videoconvert", "convertor_src1")
    if not vidconvsrc:
        sys.stderr.write(" Unable to create videoconvert \n")

    # nvvideoconvert to convert incoming raw buffers to NVMM Mem (NvBufSurface API)
    nvvidconvsrc = Gst.ElementFactory.make("nvvideoconvert", "convertor_src2")
    if not nvvidconvsrc:
        sys.stderr.write(" Unable to create Nvvideoconvert \n")

    caps_vidconvsrc = Gst.ElementFactory.make("capsfilter", "nvmm_caps")
    if not caps_vidconvsrc:
        sys.stderr.write(" Unable to create capsfilter \n")

    # Create nvstreammux instance to form batches from one or more sources.
    streammux = Gst.ElementFactory.make("nvstreammux", "Stream-muxer")
    if not streammux:
        sys.stderr.write(" Unable to create NvStreamMux \n")

    # Use nvinfer to run inferencing on camera's output,
    # behaviour of inferencing is set through config file
    pgie = Gst.ElementFactory.make("nvinfer", "primary-inference")
    if not pgie:
        sys.stderr.write(" Unable to create pgie \n")

    # Use convertor to convert from NV12 to RGBA as required by nvosd
    nvvidconv = Gst.ElementFactory.make("nvvideoconvert", "convertor")
    if not nvvidconv:
        sys.stderr.write(" Unable to create nvvidconv \n")

    # Create OSD to draw on the converted RGBA buffer
    nvosd = Gst.ElementFactory.make("nvdsosd", "onscreendisplay")

    if not nvosd:
        sys.stderr.write(" Unable to create nvosd \n")

    # Finally render the osd output
    if is_aarch64():
        print("Creating nv3dsink \n")
        sink = Gst.ElementFactory.make("nv3dsink", "nv3d-sink")
        if not sink:
            sys.stderr.write(" Unable to create nv3dsink \n")
    else:
        print("Creating EGLSink \n")
        sink = Gst.ElementFactory.make("nveglglessink", "nvvideo-renderer%u"%index)
        if not sink:
            sys.stderr.write(" Unable to create egl sink \n")

    print("Playing cam %s " %uri)
    caps_v4l2src.set_property('caps', Gst.Caps.from_string("video/x-raw, framerate=30/1"))
    caps_vidconvsrc.set_property('caps', Gst.Caps.from_string("video/x-raw(memory:NVMM)"))
    source.set_property('device', uri)
    streammux.set_property('width', 1280)
    streammux.set_property('height', 720)
    streammux.set_property('batch-size', 1)
    streammux.set_property('batched-push-timeout', 4000000)
    pgie.set_property('config-file-path', "dstest1_pgie_config.txt")
    # Set sync = false to avoid late frame drops at the display-sink
    sink.set_property('sync', False)

    print("Adding elements to Pipeline \n")
    pipeline.add(source)
    pipeline.add(caps_v4l2src)
    pipeline.add(vidconvsrc)
    pipeline.add(nvvidconvsrc)
    pipeline.add(caps_vidconvsrc)
    pipeline.add(streammux)
    pipeline.add(pgie)
    pipeline.add(nvvidconv)
    pipeline.add(nvosd)
    pipeline.add(sink)

    # we link the elements together
    # v4l2src -> nvvideoconvert -> mux -> 
    # nvinfer -> nvvideoconvert -> nvosd -> video-renderer
    print("Linking elements in the Pipeline \n")
    source.link(caps_v4l2src)
    caps_v4l2src.link(vidconvsrc)
    vidconvsrc.link(nvvidconvsrc)
    nvvidconvsrc.link(caps_vidconvsrc)

    sinkpad = streammux.get_request_pad("sink_%u"%index)
    if not sinkpad:
        sys.stderr.write(" Unable to get the sink pad of streammux \n")
    srcpad = caps_vidconvsrc.get_static_pad("src")
    if not srcpad:
        sys.stderr.write(" Unable to get source pad of caps_vidconvsrc \n")
    srcpad.link(sinkpad)
    streammux.link(pgie)
    pgie.link(nvvidconv)
    nvvidconv.link(nvosd)
    nvosd.link(sink)
    #osdsinkpad = nvosd.get_static_pad("sink")
    #if not osdsinkpad:
    #    sys.stderr.write(" Unable to get sink pad of nvosd \n")
    return source,pipeline



def main(args):
    # Check input arguments
    if len(args) < 2:
        sys.stderr.write("usage: %s <v4l2-device-path>\n" % args[0])
        sys.exit(1)

    # Standard GStreamer initialization
    number_sources=["/dev/video0","/dev/video2"]
    Gst.init(None)

    # Create gstreamer elements
    # Create Pipeline element that will form a connection of other elements
    print("Creating Pipeline \n ")
    pipeline = Gst.Pipeline()

    if not pipeline:
        sys.stderr.write(" Unable to create Pipeline \n")
    for i in range(0,len(number_sources)):
        uri = args[i+1]
        source_value, pipeline = create_source_bin(i,number_sources[i], pipeline) 
    # create an event loop and feed gstreamer bus mesages to it
    loop = GLib.MainLoop()
    bus = pipeline.get_bus()
    bus.add_signal_watch()
    bus.connect ("message", bus_call, loop)

    # Lets add probe to get informed of the meta data generated, we add probe to
    # the sink pad of the osd element, since by that time, the buffer would have
    # had got all the metadata.
    

    #osdsinkpad.add_probe(Gst.PadProbeType.BUFFER, osd_sink_pad_buffer_probe, 0)

    # start play back and listen to events
    print("Starting pipeline \n")
    pipeline.set_state(Gst.State.PLAYING)
    try:
        loop.run()
    except:
        pass
    # cleanup
    pipeline.set_state(Gst.State.NULL)

if __name__ == '__main__':
    sys.exit(main(sys.argv))

There is no update from you for a period, assuming this is not an issue anymore. Hence we are closing this topic. If need further support, please open a new one. Thanks

There are too many plugins in your create_source_bin function. You can create the plugin before nvtreammux. Then link each source_pad of bin to different sink_pad of nvstreammux.
Just like: deepstream_test_3.py

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